US4090720A - Expander spring for piston rings - Google Patents

Expander spring for piston rings Download PDF

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Publication number
US4090720A
US4090720A US05/783,450 US78345077A US4090720A US 4090720 A US4090720 A US 4090720A US 78345077 A US78345077 A US 78345077A US 4090720 A US4090720 A US 4090720A
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US
United States
Prior art keywords
oil scraper
scraper ring
channel
expander spring
radially
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/783,450
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English (en)
Inventor
Martin Morsbach
Paul Johren
Jurgen Weiss
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Goetzewerke Friedrich Goetze AG
Original Assignee
Goetzewerke Friedrich Goetze AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Goetzewerke Friedrich Goetze AG filed Critical Goetzewerke Friedrich Goetze AG
Application granted granted Critical
Publication of US4090720A publication Critical patent/US4090720A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
    • F16J9/06—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction using separate springs or elastic elements expanding the rings; Springs therefor ; Expansion by wedging
    • F16J9/064—Rings with a flat annular side rail
    • F16J9/066—Spring expander from sheet metal
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
    • F16J9/12—Details
    • F16J9/20—Rings with special cross-section; Oil-scraping rings
    • F16J9/203—Oil-scraping rings

Definitions

  • This invention relates to an expander spring for piston rings, particularly for lamina-shaped oil scraper rings and is formed of a cross-sectionally approximately U-shaped, annularly bent sheet metal strip which is rendered resilient by circumferentially distributed slots or similar cutouts and which, in the zone of at least one radial side, has axially projecting support feet for engaging at least one oil scraper ring.
  • expander spring structures which are formed of sheet metal strips of various cross-sectional configuration and are made resilient in the circumferential direction by means of slots or the like.
  • Expander springs which are particularly easy to manufacture have an L or U-shaped cross section. Expander springs of L-shaped cross section are disclosed, for example, in U.S. Pat. No. 3,627,333 which have, when viewed axially, a very small height, so that upon application of a radial tensioning force, the spring undergoes significant distortion. Further, in such expander springs there are provided no oil discharge openings so that they are practically not adapted to be used with oil scraper rings.
  • expander springs having a U-shaped cross section are more advantageous in these respects.
  • the cross-sectional profile of expander springs has been arranged in such a manner that the U profile is open either outwardly towards the wall of the cylinder in which the piston works or inwardly towards the piston, as disclosed, for example, in U.S. Pat. No. 2,837,385 and German Pat. No. 1,475,713.
  • Expander springs of the above-outlined type serve not only for the radial biasing of the oil scraper rings, but they also must guide the oil scraper rings which, in most cases, are very thin in the axial direction. Thus, the expander springs must prevent tilting of the oil scraper rings in the gap between the expander spring and the piston.
  • Expander springs with U-shaped cross section do not fully satisfy the above requirement, since the free leg ends of the "U” do not have sufficient guiding properties.
  • the expander spring disclosed in U.S. Pat. No. 3,191,947 has additional axial extensions at one of the leg ends for preventing an axial bending of the two leg ends of the "U" to one another, an expander spring having a box-like cross section resulting from such a structure is difficult to manufacture.
  • the lower leg itself of the expander spring is designed as the oil scraper and thus is exposed to a high degree of wear.
  • the expander spring for supporting an oil scraper ring in a groove of a piston is constituted by a sheet metal ring having an axis and forming an annular channel of generally U-shaped cross section.
  • the channel has two side walls, forming, respectively, a radially inner and a radially outer, axially oriented side of the expander spring.
  • the channel further has a base interconnecting the side walls and an open side opposite the base.
  • a plurality of circumferentially distributed slots are provided in the side walls for increasing the resiliency of the expander spring in the circumferential direction, and a plurality of axially projecting support feet are carried by the free end of the radially inner side of the expander spring for supporting at least one oil scraper ring.
  • the provision of the expander spring with an axially open U-shaped profile has the advantage that the tangential tension force is generated substantially by the elastic deformation of the radially extending base of the channel, while the axially oriented side walls of the channel serve for the radial and axial support of the oil scraper ring at both the inner and outer circumferences of the latter.
  • the sheet metal strip which constitutes the expander spring has, in a manner known by itself, radially oriented slots which alternatingly start from the outer and inner circumferences of the expander spring and which overlap in the base of the channel of U-shaped cross section. The radial slots thus subdivide the side walls of the channel into individual leg segments in the circumferential direction.
  • the radially outer leg segments are inclined towards the ring axis such that the free leg ends lie along a circle of smaller diameter than the portions close to the channel base.
  • a resiliently yielding axial support of the oil scraper ring in the vicinity of the outer circumference thereof.
  • the free leg ends are expediently angularly bent radially inwardly.
  • the radially inner leg segments formed by the slots have an S-shaped cross section so that the free leg ends, formed as oblique support feet, engage and support the oil scraper ring at its inner circumference both in the axial and in the radial direction.
  • an elastic centering of the expander spring within the piston ring groove is of advantage.
  • some of the radially inner leg segments extend farther towards the expander spring axis than the other leg segments.
  • individual resilient tongues are provided which engage the base of the piston groove for the radial support of the expander spring.
  • a plurality of oil scraper rings may cooperate with the expander spring.
  • a separate oil scraper ring may be provided on each radial side of the expander spring.
  • the radial base of the expander spring has, in the vicinity of its inner circumference, axially outwardly (that is, away from the channel) extending projections which may support a second oil scraper ring.
  • Such projections may be simply provided by bending tab-portions out of the plane of the sheet metal strip constituting the expander spring.
  • an expander spring with support feet for at least two oil scraper rings positioned in a piston groove, wherein the support feet for the upper oil scraper ring (oriented towards the combustion chamber defined by the cylinder in which the piston operates) lie along a circle of larger diameter than the support feet for the lower scraper ring (oriented towards the crank shaft connected to the piston).
  • This permits a smaller radial wall thickness for the upper oil scraper ring.
  • the upper oil scraper ring has a greater form-adaptability, so that it is capable of better conforming to any unevenness of the cylinder wall.
  • U.S. Pat. No. 2,107,241 discloses a piston ring having a cross-sectional shape approximating that discussed above in connection with the invention. It is noted, however, that a practically workable arrangement could be achieved only according to the invention, by providing not a piston ring but an expander spring with the cross section in question, and by utilizing such an expander spring in a piston groove for positioning at least one lamina-like oil scraper ring.
  • the known compression and oil scraper piston ring has no resiliency in the circumferential direction and thus is relatively rigid in the radial direction.
  • piston rings of such a structure have heretofore not found practical application.
  • FIG. 1a is a cross-sectional view of an oil scraper ring assembly incorporating a preferred embodiment of the invention.
  • FIG. 1b is a fragmentary perspective view of a component shown in FIG. 1a.
  • FIG. 2a is a cross-sectional view of an oil scraper ring assembly incorporating another preferred embodiment of the invention.
  • FIG. 2b is a fragmentary perspective view of a component shown in FIG. 2a.
  • FIG. 3a is a cross-sectional view of an oil scraper ring assembly incorporating still another preferred embodiment of the invention.
  • FIG. 3b is a fragmentary perspective view of a component shown in FIG. 3a.
  • FIG. 1a the oil scraper ring assembly is shown in its installed state.
  • the assembly is received in a circumferential groove 5 of a piston 4 operating in a cylinder 3 which defines, for example, a combustion chamber of an internal combustion engine.
  • the oil scraper ring assembly has an expander spring 1 and a lamina-like oil scraper ring 2 oriented towards the combustion chamber.
  • the expander spring 1 is a circularly bent sheet metal annulus shaped generally as a channel which has a U cross section and which thus has, relative to the ring axis, axially extending, radially inner and radially outer side walls as well as a radial base 8 interconnecting the side walls.
  • the open side of the channel is oriented towards the combustion chamber with which the piston is associated.
  • the expander spring there are provided circumferentially distributed slots 6 and 7 starting alternatingly in the radially outer side wall and the radially inner side wall and terminating in the radial base 8 in an overlapping relationship.
  • This arrangement provides that the expander spring resiliently yields in the circumferential direction and may therefore be radially tensioned.
  • the slots 6 and 7 are relatively wide to ensure satisfactory passage for the oil.
  • the slots 7 subdivide the radially inner side wall of the channel into individual, radially inner resilient segments 10, the free ends 11 of which are bent outwardly with respect to the channel in such a manner that the leg segments 10 have an approximately S-shaped profile. As may be observed in FIG. 1a, in the installed condition the free ends 11 exert a radial and an axial spring force on the oil scraper ring 2.
  • the slots 6 subdivide the radially outer side wall of the channel into individual, radially outer leg segments 12 serving, in essence, for the axial support of the oil scraper ring 2.
  • Each segment 12 has a portion 13 which connects the segment with the channel base 8 and which engages the wall 14 of the cylinder 3 at the crank shaft side of the oil scraper assembly.
  • this zone of each segment 12 forms a gliding shoe which glides on the oil film at the cylinder wall 14 without any appreciable scraping effect, thus avoiding a premature wear of the expander spring.
  • the engagement between the expander spring and the cylinder wall prevents the expander spring from canting in the piston groove which would adversely affect its operation.
  • the radially outer leg segments 12 extend with a slight inclination inwardly (that is, towards the spreader ring axis) to provide for an axial resiliency.
  • the free ends 15 of the leg segments 12 are radially inwardly bent and thus form a relatively large engagement face 16 for the oil scraper ring 2.
  • the expander spring 17 has a U-shaped cross section open towards the crank shaft as well as oil scraper rings 18 and 19 which are arranged at both radially extending sides (that is, the base and the open side) of the channel of the expander spring.
  • the oil scraper ring 19 has a particularly small radial width and thus is capable of conforming in an improved manner to the shape of the cylinder wall 14.
  • the expander spring 17 has in the zone of the channel base, an axially outwardly oriented projection 20 which extends annularly and which is interrupted only by slots 21.
  • Some of the radially inner leg segments constitute resilient tongues 22' which are bent radially towards the ring axis to such an extent that in the assembled state they engage the groove base 23 in the piston and thus center the entire scraper ring assembly.
  • the expander spring 24 has, for the radial support of the oil scraper ring 25 (oriented towards the combustion chamber), a plurality of support feet 26 which are bent, like tabs, axially outwardly from the radial base face.
  • the feet 26, similarly to the projections 20 of the embodiment illustrated in FIGS. 3a and 3b, are situated along a circle of greater diameter than the free leg ends 28 of the leg segments 29 serving as support feet for the scraper ring 27 (oriented towards the crank shaft).

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Springs (AREA)
  • Support Of The Bearing (AREA)
US05/783,450 1976-04-07 1977-03-31 Expander spring for piston rings Expired - Lifetime US4090720A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE2615010A DE2615010B2 (de) 1976-04-07 1976-04-07 Axial und radial spannender Spreizfederring für Ölabstreif - Kolbenringe
DT2615010 1976-04-07

Publications (1)

Publication Number Publication Date
US4090720A true US4090720A (en) 1978-05-23

Family

ID=5974682

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/783,450 Expired - Lifetime US4090720A (en) 1976-04-07 1977-03-31 Expander spring for piston rings

Country Status (8)

Country Link
US (1) US4090720A (pt)
JP (1) JPS52122713A (pt)
BR (1) BR7702147A (pt)
DE (1) DE2615010B2 (pt)
ES (1) ES227673Y (pt)
FR (1) FR2360806A1 (pt)
GB (1) GB1545436A (pt)
IT (1) IT1115639B (pt)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4183544A (en) * 1977-05-06 1980-01-15 Goetzewerke, Friedrich Goetze Ag Multi-part piston oil ring
US4629198A (en) * 1983-11-03 1986-12-16 Goetze Ag Oil scraper piston ring assembly
US5078412A (en) * 1991-01-07 1992-01-07 United Technologies Corporation Separately loaded strip seal
US7497443B1 (en) 2005-05-03 2009-03-03 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Resilient flexible pressure-activated seal
US20100065008A1 (en) * 2007-01-19 2010-03-18 Ricardo Uk Limited Pistons for internal combustion engines
US20160115812A1 (en) * 2014-10-24 2016-04-28 United Technologies Corporation Sliding seal
US10260364B2 (en) * 2015-03-09 2019-04-16 United Technologies Corporation Sliding seal
US11365641B2 (en) 2014-10-24 2022-06-21 Raytheon Technologies Corporation Bifurcated sliding seal

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH063265B2 (ja) * 1987-12-17 1994-01-12 日本ピストンリング株式会社 組合せオイルリング
US4792406A (en) * 1988-05-23 1988-12-20 Nalco Chemical Company Method for dewatering a slurry using a twin belt press with cationic amine salts

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2785030A (en) * 1955-05-19 1957-03-12 Sealed Power Corp Piston ring expander with compressed dual action
US2789022A (en) * 1955-06-15 1957-04-16 Sealed Power Corp Piston ring
US2837386A (en) * 1956-08-08 1958-06-03 Mcquay Norris Mfg Co Piston ring assemblies
US2859079A (en) * 1956-03-19 1958-11-04 Sealed Power Corp Triple seal piston ring

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR811626A (fr) * 1936-10-06 1937-04-19 Piston pour moteurs à explosion ou autres applications

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2785030A (en) * 1955-05-19 1957-03-12 Sealed Power Corp Piston ring expander with compressed dual action
US2789022A (en) * 1955-06-15 1957-04-16 Sealed Power Corp Piston ring
US2859079A (en) * 1956-03-19 1958-11-04 Sealed Power Corp Triple seal piston ring
US2837386A (en) * 1956-08-08 1958-06-03 Mcquay Norris Mfg Co Piston ring assemblies

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4183544A (en) * 1977-05-06 1980-01-15 Goetzewerke, Friedrich Goetze Ag Multi-part piston oil ring
US4629198A (en) * 1983-11-03 1986-12-16 Goetze Ag Oil scraper piston ring assembly
US5078412A (en) * 1991-01-07 1992-01-07 United Technologies Corporation Separately loaded strip seal
US7497443B1 (en) 2005-05-03 2009-03-03 The United States Of America As Represented By The Administrator Of The National Aeronautics And Space Administration Resilient flexible pressure-activated seal
US20100065008A1 (en) * 2007-01-19 2010-03-18 Ricardo Uk Limited Pistons for internal combustion engines
US8555849B2 (en) * 2007-01-19 2013-10-15 Ricardo Uk Limited Pistons for internal combustion engines
US20160115812A1 (en) * 2014-10-24 2016-04-28 United Technologies Corporation Sliding seal
US9512735B2 (en) * 2014-10-24 2016-12-06 United Technologies Corporation Sliding seal
US11365641B2 (en) 2014-10-24 2022-06-21 Raytheon Technologies Corporation Bifurcated sliding seal
US10260364B2 (en) * 2015-03-09 2019-04-16 United Technologies Corporation Sliding seal
US11359504B2 (en) 2015-03-09 2022-06-14 Raytheon Technologies Corporation Sliding seal

Also Published As

Publication number Publication date
GB1545436A (en) 1979-05-10
FR2360806A1 (fr) 1978-03-03
ES227673Y (es) 1977-12-16
JPS52122713A (en) 1977-10-15
IT1115639B (it) 1986-02-03
DE2615010B2 (de) 1980-03-06
DE2615010A1 (de) 1977-10-20
ES227673U (es) 1977-08-16
BR7702147A (pt) 1978-01-10

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